Gordon Brown has a new idea about how to "make poverty history" in time for the G8 summit. With Washington so far refusing to double its aid to Africa by 2015, the chancellor is appealing to the "richer oil-producing states" of the Middle East to fill the funding gap. "Oil wealth urged to save Africa," reads the headline in the Observer.

Here is a better idea: instead of Saudi Arabia's oil wealth being used to "save Africa", how about if Africa's oil wealth was used to save Africa - along with its gas, diamond, gold, platinum, chromium, ferroalloy and coal wealth?

With all this noblesse oblige focused on saving Africa from its misery, it seems like a good time to remember someone else who tried to make poverty history: Ken Saro-Wiwa, who was killed 10 years ago this November by the Nigerian government - along with eight other Ogoni activists, he was sentenced to death by hanging. Their crime was daring to insist that Nigeria was not poor at all but rich, and that political decisions made in the interests of western multinational corporations kept its people in desperate poverty. Saro-Wiwa gave his life to the idea that the vast oil wealth of the Niger delta must leave behind more than polluted rivers, charred farmland, rancid air and crumbling schools. He asked not for charity, pity or "relief", but for justice.

The Movement for the Survival of the Ogoni People demanded that Shell compensate the people from whose land it had pumped roughly $30bn worth of oil since the 1950s. The company turned to the government for help, and the Nigerian military turned its guns on demonstrators. Before his state-ordered hanging, Saro-Wiwa told the tribunal: "I and my colleagues are not the only ones on trial. Shell is here on trial ... The company has, indeed, ducked this particular trial, but its day will surely come."

Ten years later, 70% of Nigerians still live on less than $1 a day and Shell is still making superprofits. Equatorial Guinea, which has a major oil deal with ExxonMobil, "got to keep a mere 12% of the oil revenues in the first year of its contract", according to a report on the CBS news programme 60 Minutes - a share so low it would have been scandalous even at the height of colonial oil pillage.

This is what keeps Africa poor: not a lack of political will but the tremendous profitability of the current arrangement. Sub-Saharan Africa, the poorest place on earth, is also its most profitable investment destination. It offers, according to the World Bank's 2003 Global Development Finance report, "the highest returns on foreign direct investment of any region in the world". Africa is poor because its investors and its creditors are so unspeakably rich.

The idea for which Saro-Wiwa died fighting - that the resources of the land should be used to benefit the people of that land - lies at the heart of every anti-colonial struggle in history, from the Boston Tea Party to Iran's turfing out of the Anglo-Iranian Oil Company in Abadan. This idea has been declared dead by the EU's constitution, by the national security strategy of the US (which describes "free trade" not only as an economic policy but a "moral principle") and by countless trade agreements. And yet it simply refuses to die.

You can see it most clearly in the relentless protests that drove Bolivia's president, Carlos Mesa, to offer his resignation. A decade ago, Bolivia was forced by the IMF to privatise its oil and gas industries on the promise that it would increase growth and spread prosperity. When that didn't work, the lenders demanded that Bolivia make up its budget shortfall by increasing taxes on the working poor.

Bolivians had a better idea - take back the gas and use it for the benefit of the country. The debate now is over how much to take back. Evo Morales's Movement Toward Socialism favours taxing foreign profits by 50%. More radical indigenous groups, which have already seen their land stripped of its mineral wealth, want full nationalisation and more participation - what they call "nationalising the government".

You can see it too in Iraq. On June 2 Laith Kubba, spokesman for the Iraqi prime minister, told journalists that the IMF had forced Iraq to increase the price of electricity and fuel in exchange for writing off past debts: "Iraq has $10bn of debts, and I think we cannot avoid this." But days before, in Basra, a historic gathering of independent trade unionists, most of them with the General Union of Oil Employees, insisted that the government could avoid it. At Iraq's first anti-privatisation conference, delegates demanded that the government simply refuse to pay Saddam's "odious" debts and opposed any attempts to privatise state assets, including oil.

Neoliberalism, an ideology so powerful it tries to pass itself off as "modernity" while its maniacal true believers masquerade as disinterested technocrats, can no longer claim to be a consensus. It was decisively rejected by French voters when they said no to the EU constitution, and you can see how hated it has become in Russia, where large majorities despise the profiteers of the disastrous 1990s privatisations and few mourned the recent sentencing of oil oligarch Mikhail Khodorkovsky.

All of this makes for interesting timing for the G8 summit. Bob Geldof and the Make Poverty History crew have called for a million people to go to Edinburgh and form a giant white band around the city centre on July 2 - a reference to the ubiquitous Make Poverty History bracelets.

But it seems a shame for a million people to travel all that way to be a giant bauble, a collective accessory to power. How about if, when all those people join hands, they declare themselves not a bracelet but a noose - a noose around the lethal economic policies that have already taken so many lives, for lack of medicine and clean water, for lack of justice.